hey guy, im in the middle of building a 383 for my 85. i bought a used chevy 350 and th350 for 400. got it home and got her open and found a ton of goodies. forged pistons new baring still have lube on them. a new high flow oil pump, and ported and polished fuley heads with new springs and valve. seems to be an amazing buy. well i was cleaning her up tonight and got to the block casting numbers and was wondering if any one could help me find out were this motor came from..


10w280735

v03066nn

 

Recheck those numbers

v03066nn. The last 6 is wrong

 

your right its only one one 6.

v0306nn

 

I can't find a NN suffix code. Are you sure those are N's? The stamped numbers are usually hard to read depending how hard they were stamped into the block.

 

The head casting number is a lot more meaningful than the block numbers, now that it's been rebuilt.

 

moring guys, well thanks for the help so far, i went out to the shop this moring and recheck the numbers again. i was wrong about one of te numbers here it is.

v0306cnn

i also pulled the number off the head, here they are.
3782461
h255

 

ok guys im getting a bit confused, the numbers i gave you guys are stamped on the left side of the motor if your looking at it. th numbers are stamped in a place were the heads would cover it now i donut no if those are the casting number or if the 3970010 is the casting number can some one help me out here?

 

3970010 is the casting number.

 

The 010 casting just tells you it's a 4" bore block. GM must have produced about a million of those castings. It's probably the most used casting in any rebuild.

OK now

V = Flint engine plant
0306 = Mar 6
CNN = 1970 350. It had a TH350 behind it. It was rated at 250 HP with a 2BBL. The engine was used in A, F and X body cars.

What do you have now? A .030" over 1970 350 block stroked out to 383.

Don't get over excited about the 461 heads. They were a hot item 30+ years ago. There are much better choices available now either OEM or aftermarket.